Ultra-Wideband PA Input Combining for Low-Duty-Cycle Power Saving
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Solution Overview
Problem
Conventional methods for reducing power consumption in ultra-wideband power amplifiers, particularly those with low duty cycles, are inefficient due to high capacitance in bias circuits and cannot effectively manage very short RF pulses, leading to continued power consumption during quiet periods.
Innovation Solution
A power amplification unit that combines an RF signal with an auxiliary signal, generated to have a pulse-shaped component and a quiet period component with a frequency spectrum lower than the RF signal, to prevent amplification and reduce power consumption during off periods, using an output matching circuit with signal filtering parameters to pass the amplified output above a cutoff frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional PA bias voltage control methods are used to reduce power consumption during quiet slots, then power consumption is reduced, but the method cannot effectively manage very short RF pulses and continues to consume power during quiet periods due to high capacitance in bias circuits
Solution Approach 1:
The auxiliary signal is generated in advance to preemptively prepare the power amplifier for upcoming RF pulses. By providing this preliminary signal during quiet periods, the PA is pre-conditioned to rapidly respond to short pulses without requiring continuous bias voltage adjustments, thus solving both the power consumption and responsiveness issues
Solution Approach 2:
An auxiliary signal is introduced as an intermediary element between the control system and the power amplifier. This auxiliary signal, which contains a quiet period component, acts as a mediator that prepares the PA for upcoming pulses without requiring continuous power consumption, effectively bridging the gap between pulse intervals
2Reliability
If the power amplifier operates continuously to maintain readiness for RF pulses, then signal quality is maintained, but power consumption continues during quiet periods between pulses
Solution Approach 1:
The auxiliary signal is applied periodically in sync with the RF pulse train, providing preparation only during the necessary intervals. This periodic application allows the PA to be reset to a low-power state during quiet periods while maintaining readiness for the next pulse, achieving both energy savings and signal quality
Solution Approach 2:
The auxiliary signal changes the operating parameters of the power amplifier during quiet periods by providing a preparatory voltage level. This parameter change allows the PA to transition to a low-power state between pulses while maintaining the capability to rapidly respond to incoming RF signals, thus reducing power consumption without sacrificing signal quality
Data Source
AI summary
Power amplification units and methods are provided, which use a combiner and an auxiliary signal to feed the power amplifier (PA) with a signal that prevents or reduces operation of higher amplification stages during off periods of the received RF signal. The PA output is delivered through an output matching circuit configured to pass the RF signal and attenuate the auxiliary signal; and the combiner combines the RF signal and the auxiliary signal through respective filters to generate the RF input signal to the PA. An auxiliary signal generator may be configured to generate the auxiliary signal with relation to the RF signal as having a frequency spectrum lower than a cutoff RF frequency. Resulting lower power consumption, particularly in case of low duty cycle RF signals, reduces heating, enables longer battery use and increases reliability performance.